Embodiments disclosed herein relate to methods for enhancing purification of proteins, including antibodies. They particularly relate to methods for reducing the level of aggregates and can be combined with methods of cell culture harvest clarification. They further relate to integration of these capabilities with other purification methods to achieve a desired level of protein purity.
Aggregate removal is an important aspect of protein purification. It has been shown that low concentrations of the yellow fluorescent heterocyclic dye ethacridine reduces aggregate content of antibody preparations, and that this result may be the result of chromatin removal (Gan et al J. Chromatography A 1291 (2013) 33-40). Ethacridine has a long history as a protein precipitating agent.
The aryl anionic dye Methyl Blue is used for histological staining and has been used to mediate electron transfer in microbial fuel cells. Methyl blue is also known by the names Cotton Blue, Helvetia Blue, and Acid Blue 93. The reagent has not been employed in the field of protein fractionation.